Applicants' co-pending application Ser. No. 76,217 filed Sept. 17, 1979 (i.e. the Hicks/Pleass application) relates to a wave powered desalination apparatus which incorporates a pressurized piston pump for delivering raw seawater under substantial pressure to desalination means such as a reverse osmosis device. The Hicks/Pleass application points out the need for such a device and the advantages resulting from the particular device described therein. In addition to the general need for an effective desalination device, it would also be desirable if use could be made of wave movements to provide not only an improved desalination device but also to accomplish other desirable results. For example, with the growing interest in mariculture, it would also be desirable if some means could be provided whereby the nutrient rich bottom water could be transported closer to the water surface so as to aid in mariculture.